Selected DOS and BIOS Service Routines


BIOS Service 16/00: read keyboard character


BIOS Service 1A/02: read real-time clock


DOS Service 21/02: display single character to monitor


DOS Service 21/05: print character


DOS Service 21/09: display character string to monitor


DOS Service 21/4C: end program execution and return to DOS


DOS Service 27: terminate program but keep program resident in memory (TSR)